Foundations for California's Water Security in a Changing Climate

California’s water supplies are facing unprecedented stresses, and the state’s water-management systems are struggling to meet both environmental and human needs (agricultural, municipal, industrial). Supplies are highly vulnerable to climate variability and extreme events, limiting options to respond to the combined stresses of a changing climate, population, and land cover. Strategic, coordinated investments in California’s water infrastructure, institutions, and information will provide the foundation for a secure, equitable, and efficient water future. The cornerstone of water security, and priority need for California, is a modern, robust water-information system that enables accurate, timely, and transparent accounting through the water-supply and use cycle. This system must extend from mountain headwaters through valley groundwater. Investments are also needed in capacity building for use of water information among institutions and stakeholders across the state. Priority infrastructure improvements are needed for central elements of the state’s “green” infrastructure: restoration of Sierra Nevada and other forests in source-water areas, and additional groundwater recharge on farmland and expanded floodplains. With better-informed management, California’s existing water supplies could go further to meeting the state’s urban, agricultural, ecological, and industrial needs